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Topic Title: Sony 46" LCD TV: vertical strip After 4 years 8 months of use Topic Summary: Would a professional consider this normal wear and tear or it's unusual?Created On: 03 September 2012 12:10 PMStatus:
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My Sony KDL46D3500 46" LCD TV is 4 years 8 months old and it developed a fault whereby there's a clearly visible vertical line from top to bottom. Does this happen often? In a professional opinion, would one normally expect the TV to fail like that after 4-5 years of use? I think it should not. My opinion is that LCD screens are designed and built to last for much longer than that. Am I wrong? I am trying to argue with a retailer that I was unlucky to buy a defective TV set from the beginning (a manufacturer's defect that caused 1 bit of address line to fall off after 4 years of use, for example).

"Does this happen often?"
It does not really matter - if it's a fault, it is there.

"...built to last for much longer than that. Am I wrong?"
The design will last forever, but components fail during their working life; generally without predicition.

"I am trying to argue with a retailer that I was unlucky to buy a defective TV set from the beginning (a manufacturer's defect that caused 1 bit of address line to fall off after 4 years of use, for example)."
You will have to explain this in better terms.

For over 4.5years the TV presumably has functioned without fault.
On the other hand my 40year old Sony 13" has never gone wrong but suffers tube low emissions..as predicted at the design stage.

"Does this happen often?"
"It does not really matter - if it's a fault, it is there. "
Well since you can't directly prove the fact that there was a fault 4 years ago at the time of purchase, it is generally accepted by court that if this is an exceptional occurrence and such a TV should have normally lasted longer, then it must have been a fault from the beginning.

"...built to last for much longer than that. Am I wrong?"
"The design will last forever, but components fail during their working life; generally without predicition. "
That's right, the question is whether from your qualified point of view this happens often or rarely.

"I am trying to argue with a retailer that I was unlucky to buy a defective TV set from the beginning (a manufacturer's defect that caused 1 bit of address line to fall off after 4 years of use, for example)."
"You will have to explain this in better terms. "
I think my first paragraph above explains it. If I prove that it's an exceptional event for such a TV to fail within 4 years, this will most likely be considered by a court (if it ever goes to court!) to be a proof of the fact that my TV was initially defective which then according to Sales of Goods Act 1979 forces the retailer to replace/repair it.

"For over 4.5years the TV presumably has functioned without fault.
On the other hand my 40year old Sony 13" has never gone wrong but suffers tube low emissions..as predicted at the design stage.
It's not normal wear - it is faulty."

That's what I mean - I am on good terms with electronics myself and I've been repairing old CRT TVs as a hobby 15 years ago and I strongly believe that an LCD screen should live for much longer than 4-5 years. Just wanted to prove for myself that I am not going crazy and that it's not like these days most of LCD TVs do not last longer than 4-5 years.

Originally posted by: ylexus"I am trying to argue with a retailer that I was unlucky to buy a defective TV set from the beginning (a manufacturer's defect that caused 1 bit of address line to fall off after 4 years of use, for example)."

"You will have to explain this in better terms. "

I think my first paragraph above explains it. If I prove that it's an exceptional event for such a TV to fail within 4 years, this will most likely be considered by a court (if it ever goes to court!) to be a proof of the fact that my TV was initially defective which then according to Sales of Goods Act 1979 forces the retailer to replace/repair it.

The retailer will pass this back to Sony. Sony will state that the MTBF of the design is fit for purpose, but any MTBF will have a distribution curve and your failure is just a point on this curve. Unless you can prove that a high percentage of this model of TV show this failure then I can't see that you have a case.

I disagree slightly with the previous poster, it is not "wear", but it would not be unexpected for a fault to randomly occur after that period of time. I get the impression you are hoping for a "professional statement" here to support your case: I regret to say that no reliability engineer is going to state that any semiconductor component will last for a specific length of time. The fact is that they are subject to random failures, and there's nothing the manufacturer can do about that. You could even generalise and say that more modern equipment will have a tendency to fail in a shorter space of time to 40 year old equipment because it has more (vastly more!) transistor junctions in. It's not quite linear, because manufacturing methods have improved, but 4y8m sounds pretty good going to me for a piece of modern domestic equipment.

But if you are really bothered, I would recommend that you find Sony discussion forums to see if there is a history of failures with this model, then maybe you will have grounds for a group action.

On another issue, that's why I prefer FM radios to DAB: less bits in to go wrong!! (And they draw less power, and turn on straight away...)

I understand that any electronic device can fail at any point in time. I think what makes difference is where on this curve the event occurred. If number of such TVs that fail before 4y8m is significantly smaller than those that fail after that, then this can be explained by the responsible transistor(s) in my set being defective from the beginning, that is, significantly less reliable than all similar transistors in most of the other TVs.

Another point. If everything else fails, provided that this is not a permanent electronics failure but simply a bad connection in the inter-board connector, what is the chance of me discovering this connection issue inside the TV? Is it all solid block inside or the actual video memory electronics is accessible? My hopes lie in the fact that when it first occurred it used to disappear after 15-20 min of functioning, bit then now it hardly disappears at all. I used to fix old CRT TVs and assemble ZX Spectrums from ICs many years ago so no newbie to hands-on electronics.

I once had a similar fault. It was caused by a pulse from the VCR on a shelf below. A sheet of aluminium food wrap glued to underside of shelf cured it. I had intended to earth the sheet but it proved unnecessary.

I have spent many years working in the domestic electronics industry, this is a comm problem, it is an internal connection problem with the screen, Sony are aware of this and may offer a replacement screen. However they have replaced the complete TV in some cases. I assume your dealer is a an approved Sony service center. If all else fails you could ring Sony customer support.